- #1
DSM_
- 3
- 1
If there were no spring then the answer come out to be (6/5)m. Please help.
What is the solution to the Wedge-Spring-Block Problem?
- Thread starter DSM_
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Homework Help Overview
The discussion revolves around a problem involving a wedge, spring, and block, focusing on the dynamics of the system and the role of gravitational and spring forces. Participants are exploring the implications of the spring's behavior on the overall mechanics of the problem.
Discussion Character
- Exploratory, Assumption checking, Conceptual clarification
Approaches and Questions Raised
- Participants discuss the effects of the spring on the system, with some questioning whether the spring's presence is significant. There are attempts to apply conservation of energy principles and to clarify the conditions under which the block is released. The relevance of the spring's initial state (taut or relaxed) is also debated.
Discussion Status
There is ongoing exploration of different interpretations of the problem, particularly regarding the assumptions made about the spring's state. Some participants have suggested that energy conservation might lead to a specific answer, while others express uncertainty about the problem's wording and intent.
Contextual Notes
Participants note the lack of clarity in the problem statement regarding the initial conditions of the spring and the block, which may affect the interpretation of the solution. The discussion reflects a mix of assumptions and interpretations that have not yet reached a consensus.
If there were no spring then the answer come out to be (6/5)m. Please help.
- #2
AlephNumbers
- 293
- 33
Have you learned about gravitational potential energy and spring energy yet?
- #3
- 42,906
- 10,526
I agree, and since k does not appear in any of the answers, the questioner agrees the spring is irrelevant.DSM_ said:
My guess is that the coefficient was supposed to be 1/4.
- #4
AlephNumbers
- 293
- 33
Even when the gravitational force exerted on the block M is equal to the spring force exerted on block M, the block is still moving. Your method presumes that this is not true. If you use conservation of energy to solve for the maximum spring force, answer (A) can be arrived at.
Last edited:
- #5
- 42,906
- 10,526
You are assuming that block M is released with the spring just taut, i.e. at its relaxed length. Yes, that gives answer A, so that is probably what is intended, but I see nothing in the problem statement to justify that assumption.AlephNumbers said:
- #6
DSM_
- 3
- 1
Okay, I have to do it with energy conservation.
If block is released when spring is relaxed, if it moves x downwards,
Work done by grav = Potential energy of Spring.
1/2kx^2 = Mgx
kx = 2Mg
Then tension is kx everywhere in string. Then equating to (friction + mgsin37) gives answer (A).
Is this correct?
If block is released when spring is relaxed, if it moves x downwards,
Work done by grav = Potential energy of Spring.
1/2kx^2 = Mgx
kx = 2Mg
Then tension is kx everywhere in string. Then equating to (friction + mgsin37) gives answer (A).
Is this correct?
- #7
- 42,906
- 10,526
Seems so. Still a poorly worded question, and congratulations to AlephNumbers for guessing what was meant.DSM_ said:
- #8
DSM_
- 3
- 1
haruspex said:
I think questioner want us to assume that the spring is relaxed otherwise there wouldn't be any spring at all.
Yup, thanks AlephNumbers :)